Cost Evaluation of Columns Arrangements in Special Steel Moment Resisting Frames with Special Chevron Braces

Building structures are subject to displacement under the influence of forces resulting from earthquake. The most common method of controlling such displacements in steel structures, which are usually of lateral type, is the use of braces. Depending on designing requirements and feasibility, braces are available in various forms. Configuration of bracing systems is generally of concentric or eccentric type. Concentric bracings greatly increase the structural stiffness compared to the moment resisting frame, and limit the lateral displacement of the structure. On the other hand, given the great importance for the construction cost, finding the best type of structure in terms of the distance of columns/beam spans, number of stories on different soil types has been studied in this paper. In this paper, special steel moment resisting frames with chevron eccentric bracing with various storey numbers and spans with two soil types (types II and III) have been analyzed and designed according to the considerations of American and Iranian regulations and codes. The obtained results have been presented and compared as some charts and graphs. Based on the results, in soil type II, 7.5m span has been obtained as the optimal model for 5, 10, and 15-story buildings. In soil type III, 7.5m span is the most optimal model in 5-storey buildings.